Heeran Lee

3D Hand Anthropometry of Korean Teenager’s and Comparison with Manual Method

The requirements of wearing products fitting comfort was continuously increasing and considerable attentions had been paid for a long time. The assessment of the physical dimensions of the human hand provided a metric description to establish human-machine compatibility. Higher accuracy in hand anthropometric measurements could be achieved with the aids of an image analysis system. Scanning of hand surfaces either 2D or 3D was an alternative method for manual measurements. Three-dimensional anthropometry may lead to significant improvement in fitting comfort of wearing products. The purpose of this study was to measure 3D hand anthropometry and compared it with manual methods. For that purpose, 10 hand measurements of the right hand (lengths, breadths, and circumference of hand and fingers) were taken from 1,700 middle and high school students by age ranged from 13 to 19 years old. The hand was measured by manual (using anthropometric sliding, spreading calipers and measuring tape) and using a high-resolution 3D hand scanner (NEXHAND H-100, Knitech, South Korea) with the scanning accuracy ± 0.5 mm. From the scanned data, the hand measurements were extracted using scanning software (Enhand, Knitech, South Korea). Mean and standard deviation for each hand measurements were calculated. T-test statistical test on the data revealed that there was no significant difference between the manual and 3D hand measurements (p > 0.05). Therefore, 3D anthropometry can be replaced with manual methods. The data gathered may be used for ergo-design applications of hand tools and devices. And also it can provide a great help to develop a hand anthropometry database for hand wearing products.

Evaluation of the Functional and Non-functional Seat Sponge Effect in Sitting Chairs

Objective: The purpose of this study was to evaluate comfort levels of functional and non-functional chairs using subjective comfort rating, interface pressure measurement, muscle activity measurement, and skin temperature measurement. Background: Chairs are used for a prolonged period of time for sitting in many places such as the office, at university, at school, in industry, and so on. Almost all people use chairs in their everyday life. The functional properties of the chair are associated with comfort. Method: The subjective evaluation contains questions regarding chair comfort which can be rated with five point scale. The body-seat interface pressure was measured using a pressure mat system. The symmetry of sitting was measured using electromyography. The change in body part (thigh and buttock) temperature before and after sitting on a chair was measured with an infrared camera. Results: Participants rated significantly (p Conclusion: Overall, interface pressure measurement, muscle activity measurement, thermal imaging and subjective comfort score results showed that the functional chair was more comfortable than the non-functional chair. Application: The adopted methodologies could be used to measure the seating comfort of train seats.